EVALUATION OF A PORTABLE NITRATE ION-SELECTIVE ELECTRODE WITH AQUEOUS POTASSIUM NITRATE AND VEGETABLE JUICE

The nitrate ion content of vegetables has become a concern with regard to human health.
A portable nitrate ion-selective electrode (ISE) developed by Horiba, Ltd. was evaluated against an aqueous solution of potassium nitrate and vegetable juice.
The ISE exhibited a linear dynamic range from 20 to 6000 ppm NO₃^– in standard aqueous solutions of potassium nitrate.
In vegetable juice, the measured nitrate ion concentration decreased proportionately with dilution, and was constant as a function of temperature.
In nitrate-spiked samples of raw vegetable juice, the recovery percentage consistently approached 100%. Furthermore, the ISE results were essentially identical to those obtained by ion chromatography (IC), exhibiting a correlation coefficient of R=0.997 (n=7). The use of an ionic strength adjustor was deemed unnecessary in these experiments, which allows for simple implementation in practical applications.
The instrument is currently commercially available as the compact nitrate ion meter B-343 (Horiba Ltd, Kyoto, Japan).

International Symposium on Vegetable Safety and Human Health

H. Ito

Brassica campestris, spinach, celery, Japanese radish, turnip, non-suppressor ion chromatography, ISE

https://doi.org/10.17660/ActaHortic.2010.856.19